I agree that boys don’t want to stop whatever they are doing to go to the bathroom!
I think wearing the cloth underwear helps. When leaving home or during the night, I used to put the “pull-up” disposible training diapers OVER the underwear. If the child wet himself, at least the entire outfit or bed didn’t get wet, and if the child didn’t have an accident, I could re-use the “pull-up” another time.
During the training time, I said repeatedly throughout the day, “time for potty!” Whenever the child used the toilet, I would simply say, “Ah, doesn’t that feel better than wet clothes?” I never overly-praised or said much more than that.
For the record, I thought my DD was much harder to train than my DS. Gender might play a role, but I think personality has a lot to do with it. My DS is always ready to move up to the next developmental stage before I’m ready for him, while my DD takes her own sweet time growing up. (And this is one reason I’m grateful to homeschool…they can grow at their own speed.)
Good luck. He will eventually be trained, I have no doubts about that. 🙂